Seismic Behavior of RC Shear Walls Strengthened with Fiber-Reinforced Polymer
Publication: Journal of Composites for Construction
Volume 17, Issue 5
Abstract
This paper investigates the seismic behavior of RC shear walls strengthened by using carbon fiber-reinforced polymer (CFRP) composites. Three RC shear walls were tested: one control wall and two walls strengthened by fiber-reinforced polymer (FRP), using two different strengthening schemes. The walls were tested when subjected to a constant axial load along with synchronized cyclic moment and shear force at the top of the tested panel. The primary purpose of the FRP retrofit schemes was to increase the flexural and shear capacities of wall panels that experienced higher seismic demands than the design ones. The walls represent the sixth story panel of an eight-story RC, moderately ductile, shear wall designed according to the 2005 National Building Code of Canada. Reported shake table tests on two eight-story walls demonstrated the increase in the demand in higher story levels as a result of the effect of higher modes of vibration, which calls for increasing the capacity of the walls at a high floor level. In this study, the first wall was strengthened by using two layers of unidirectional CFRP sheet that were applied vertically and anchored to the top and bottom slabs, above which unidirectional horizontal C-shaped CFRP sheets were applied. The second wall was strengthened by applying cross-FRP bracings on the two sides of the wall. The three walls were tested under constant axial load and with increasing cycles of synchronized top moment and lateral load with a top moment-to-shear ratio of 2.75 up to failure. The strengthened walls showed satisfactory performance with improved flexural and shear strengths compared to the control wall. The two retrofitted walls showed different load and deformability capacities because of the nature of crack propagation and the orientation of the applied CFRP sheets.
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Acknowledgments
The authors are grateful for the financial support received for this study from the Natural Sciences and Engineering Research Council of Canada (NSERC), le Fonds de la Recherche du Québécois sur la—Nature et les Technologies (FRQNT) and Centre d’Études Interuniversitaire sur les Structures sous Charges Extrêmes (CEISCE). The authors also acknowledge Fyfe Co. for donating the FRP composite materials used in this research.
References
ACI Committee 440. (2008). “Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures.”, American Concrete Institute, Farmington Hills, MI.
Antoniades, K., Salonikios, T., and Kappos, A. (2003). “Cyclic tests on seismically damaged reinforced concrete walls strengthened using fiber-reinforced polymer reinforcement.” ACI Struct. J., 100(4), 510–518.
Bakis, C., et al. (2002). “Fiber-reinforced polymer composites for construction—State-of-the-art review.” J. Compos. Constr., 6(2), 73–87.
Burr, A. (2004). “Recent development in the use of FRP anchors and masonry wall strengthening techniques.” Struct. Eng., 82(18), 20–21.
Canadian Standards Association (CSA). (2004). “Design of concrete structures.”, Mississauga, Ontario, Canada.
Effendy, E., Liao, W., Song, G., Mo, Y., and Loh, C. (2006). “Seismic behavior of low-rise shear walls with SMA bars.” Proc., 10th Biennial Int. Conf. on Engineering, Construction, and Operations in Challenging Environments, Earth and Space, ASCE, Reston, VA.
Elnashai, A., Pilakoutas, K., and Ambrayses, N. (1990). “Experimental behavior of reinforced concrete walls under earthquake loading.” J. Earthquake Eng. Struct. Dyn., 19(3), 387–407.
El-Sokkary, H., Galal, K., Ghorbanirenani, I., Léger, P., and Tremblay, R. (2013). “Shake table tests on FRP-rehabilitated RC shear walls.” J. Compos. Constr., 17(1), 1–12.
Fiorato, A., Oesterle, R., and Corley, W. (1983). “Behavior of earthquake resistant structural walls before and after repair.” ACI J., 80(5), 403–413.
Fyfe Company. (2010). “Tyfo SCH-11UP composite using Tyfo S Epoxy user’s guide.” 〈http://www.fyfeco.com〉 (Jan. 12, 2010).
Ghorbanirenani, I., Tremblay, R., Léger, P., and Leclerc, M. (2012). “Shake table testing of slender RC shear walls subjected to eastern North America seismic ground motions.” J. Struct. Eng., 138(12), 1515–1529.
ISIS Canada. (2008). “FRP rehabilitation of reinforced concrete structures.” ISIS design manual 4, Canadian Network of Centers of Excellence on Intelligent Sensing for Innovative Structures, Canada.
Kanakubo, T., Aridome, Y., Fujita, N., and Matsui, M. (2000). “Development of Anchorage system for CFRP sheet in strengthening of reinforced concrete structures.” Proc., 12th World Conf. on Earthquake Engineering (CD-ROM), New Zealand Society for Earthquake Engineering, Upper Hutt, New Zealand.
Khalil, A., and Ghobarah, A. (2005). “Behaviour of rehabilitated structural walls.” J. Earthquake Eng., 9(3), 371–391.
Kim, S., and Smith, S. (2009). “Behaviour of handmade FRP anchors under tensile load in uncracked concrete.” J. Adv. Struct. Eng., 12(6), 845–865.
Lombard, J., Lau, D., Humar, J., Foo, S., and Cheung, M. (2000). “Seismic strengthening and repair of reinforced concrete shear walls.” Proc., 12th World Conf. on Earthquake Engineering (CD-ROM), New Zealand Society for Earthquake Engineering, Upper Hutt, New Zealand.
National Research Council of Canada. (2005). National building code of Canada, 12th Ed., Institute for Research in Construction, Ottawa, Ontario, Canada.
Orton, S., Jirsa, J., and Bayrak, O. (2008). “Design considerations of carbon fiber anchors.” J. Compos. Constr., 12(6), 608–616.
Ozbakkaloglu, T., and Saatcioglu, M. (2009). “Tensile behaviour of FRP anchors in concrete.” J. Compos. Constr., 13(2), 82–92.
Panneton, M., Léger, P., and Tremblay, R. (2006). “Inelastic analysis of a reinforced concrete shear wall building according to the national building code of Canada 2005.” Can. J. Civ. Eng., 33(7), 854–871.
Paterson, J., and Mitchell, D. (2003). “Seismic retrofit of shear walls with headed bars and carbon fiber wrap.” J. Struct. Eng., 129(5), 606–614.
Priestley, M., and Amaris, A. (2002). “Dynamic amplification of seismic moments and shear forces in cantilever walls.”, Rose School of Engineering, Pavia, Italy.
Priestley, M., Seible, F., and Calvi, G. (1996). Seismic design and retrofit of bridges, Wiley, New York.
Taghdi, M., Bruneau, M., and Saatcioglu, M. (2000). “Seismic retrofitting of low-rise masonry and concrete walls using steel strips.” J. Struct. Eng., 126(9), 1017–1025.
Vecchio, F., Haro de la Pena, O., Bucci, F., and Palermo, D. (2002). “Behavior of repaired cyclically loaded shear walls.” ACI Struct. J., 99(3), 27–334.
Information & Authors
Information
Published In
Journal of Composites for Construction
Volume 17 • Issue 5 • October 2013
Pages: 603 - 613
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Jul 15, 2012
Accepted: Jan 16, 2013
Published online: Jan 18, 2013
Discussion open until: Jun 18, 2013
Published in print: Oct 1, 2013
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